Azo dyestuffs of the pyrazolone series



United States Patent AZO DYEQTUFFS OF THE PYRAZOLONE SERIES Piero Maderni, Hans Ruckstuhl, and Willy Steinemann, Basel, Switzerland, assignors, by mesne assignments, to Saul & Co., Newark, N. 1., as nominee of Fidelity gnion Trust Company, executive trustee under Sandoz rust No Drawing. Application March 29, 1954 Serial No. 419,608

Claims priority, application Switzerland April 2, 1953 6 Claims. (Cl. 260-147) The present invention relates to new azo dyestuffs of the py-razolone series and to their chromium complex wherein R stands for the radical of a l-aryl-3-methy1-5- pyrazolone which is free of sulfonic acid and carboxylic acid groups but may be further substituted in the aryl residue as hereinafter specified and which is bound to --N=N in its 4-position, R stands for alkyl, alkoxyalkyl, cy-cloalkyl, aralkyl or a-ryl free of sulfonic acid and carboxylic acid groups, and R stands for hydrogen or alkyl or, together with N-- and R for a heterocyclic residue, and wherein the group stands in para-position to COOH or -N=N-.

A preferred series of the new azo dyestuffs correspond in the metal-free form to the formula wherein R and R have the previously-recited significances, wherein the position of the group is as afore-recited, and wherein the nucleus A may be monosubstitute-d in position 3 or 4' or disubstituted in the positions 2', 3' or 2', 4' or 2, 5' or 3, 4' or 3', 5' by halogen atoms, cyano, alkyl and/or a'lkoxy groups.

The azo dyestuflfs according to the invention which are metallized in substance, contain preferably less than two atoms of chromium per two molecules of monoazo dyestuff, for instance one atom of chromium for two 2,821,5'24 Patented Jan. 28, 1958 molecules of monoazo dyestulf. The latter correspond to the general formulae /R1 SOr-N RI and respectively, wherein O l R has the significance corresponding to the previously-recited and the significances of the symbols R R and A are the same as mentioned above. The group stands in para-position to COO- or N=N--.

The new azo dyestuffs of the pyrazolone series of the present invention are obtained by coupling one mole of the diazo compound of a 1carboxy-2-arninobenzene-sulfonic acid amide which corresponds to the formula wherein R and R have the previously-recited significances and the group is in para-position to the carboxyl or to the amino group, with one mol of an unsulfonated and non-car boxylated 1-aryl-3 methyl-S-pyrazolone which may be further substituted as described in the aryl radical, and then treating the so-obtained monoazo dyestufi in substance or on the fiber with a chromium-yielding agent.

The coupling of the diazo compound with the pyrazolone is advantageously carried out in alkaline medium; the working up and isolation of the obtained monoazo 3 dyestuff may be carried out in essentially conventional manner, e. g. by filtering, washing and drying.

Suitable diazo components for the purposes of the presentinvention are l-carboxy-2-aminobenzene-4- or sulfonic acid amides, in which one hydrogen atom of the sulfonic acid amide group is replaced by alkyl, alkoxyalkyl, cycloalkyl, or unsulfonated and non-carboxylated aralkyl or aryl-the alkyl being lower alkyl-and the other hydrogen atom of the said sulfonic acid amide group may be replaced by lower alkyl. Moreover, the two hydrogen atoms of the sulfonic acid amide group may be replaced by groups which, with the nitrogen atom, form a heterocyclic group.

The l-aryl-3-methyl-5-pyrazolones, employed as azo components, are selected from the 1-phenyl-3-methyl-5 pyrazolone and the l-naphthyl-3-methyl-5-pyrazol0ne series. Especially, suitable are the l-phenyl-3-methyl-5- pyrazolones which correspond to the formula These are advantageously mouosubs tituted in the 3- or 4'-position or disubstituted in the 2',3'- or 2',4'- or 2' .5- alkyl and/ or lower alkoxy.

Ofthe: 1-naphthyl-3-methyl-5-pyrazolones, the l-naphthyl(1 and 2')-3-methyl-5-pyrazolones and their derivatives which are partly or entirely hydrogenated in the naphthyl moiety are particularly useful.

For conversion thereof in to the chromium-containing azo dyestuffs, the monoazo compounds are advantageously treated in aqueous solution and at elevated temperature with chromium salts, for example with sodium chromate, potassium chromate, sodium bichromate or potassium bichromate or with complex salts such as sodium chromium tartrate or potassium chromium tartrate or the like. Those metalliferous azo dyestuffs are particularly interesting which contain less than two atoms, for example about one atom, of chromium for two molecules of monoazo dyestufi. Chromium complex compounds of this type are generally designated 1:2-complexes.

The new monoazo dyestuffs are, in non-metallized form, products which are suitable for dyeing wool by the afterchroming process and especiallyby the single bath-chroming process. In this way, level full yellow shades of very good fastness to light, washing and fulling are obtained. The azo dyestuffs which are chromed in substance dye wool and silk from neutral or weakly acid dyebaths in level full yellow shades having very good fastness properties; they are also excellently suited for dyeing synthetic nitrogenous fibers, such as synthetic polyamide fibers, and for dyeing leather.

The following examples set forth presently-preferred illustrativev embodiments of the invention which, however, is not at all limited to such embodiments. In the examples, the parts and percentages are by weight, and the temperatures are in degrees centigrade.

Example 1 23 parts of 1-carboxy-2-aminobenzene-5-sulfonic acid methylamide are dissolved in 200, parts of water together.

with parts of an aqueous sodium hydroxide solution of strength. 6.9 parts of sodium nitrite are added to the resultant solution, which is then added dropwise to a mixture of parts of concentrated hydrochloric acid and carbonate and 300parts of water. The-massis: stirred To prepare the chromium complex compound in substance, a portion of the obtained filter-cake corresponding to 8.3 of the-dried dyestuff is suspended in 230 parts of water. A complex chromium sodium tartrate solution consisting of 10 parts of potassium chromium (III) sulfate, 23 parts of a 13% aqueous tartaric acid solution and 9.3 parts of a 30% aqueous sodium hydroxide solution is added to the suspension, and the mass is boiled for 20 hours under reflux. The precipitated chromium-containing azo dyestutf is filtered ofi, the filter cake is dissolved in hot dilute aqueous sodium hydroxide solution, the dyestuif precipitated from the solution by the addition of sodium chloride, again filtered OE and finally dried at under reduced pressure. It corresponds to the formula and is a brown-yellow powder, which dyes wool, silk and synthetic polyamide fibers from a weakly acid bath in yellow shades which are fast to light, washing and fulling.

Example 2 By replacing the 19.1 parts of l-phenyl-3-methyl-5- pyrazolone in Example 1 by the equivalent amount of 1- (3-chloro)-phenyl-3-methyl-5-pyrazo1one, and otherwise proceeding as described in the said example, there is obtained a monoazo dyestufi which also dyes wool by the single bath chroming process in shades which are fast to light, washing and fulling. It corresponds to the formula H: C-HN 0 28- For conversion thereof into the chromium complex I compound, 4.5 parts of the dyestutf are dissolved in 250 parts of water at 95-97", with the addition of sodium hydroxide. To the resultant solution, there is added a solutionwhich has been adjusted to neutrality with the aid of sodium hydroxideof'3. parts of crystalline sodium bichromate and 20 parts of water, and the mass is heated to boiling while. stirring. The pH is then adjusted to 11.2- 11.3 by the addition of acetic acid, and boiling is thereupon continued until the metallizationis completed. The chromium-containing. azo dyestufi is precipitated by means of sodium chloride, after which it is filtered cit and dried at 95 under reduced pressure. It compo ads to the formula I N HaC-HN 0 S and is a brown-yellow powder which dyes wool, silk and synthetic polyamide fibers from a weakly acid bath in yellow shades which are fast to light, washing and fulling.

Example 3 5.7 parts of the monazo compound, obtained after the manner described in Example 1 by coupling diazotized 1-carboxy-2-aminobenzene-S-sulfonic acid morpholide with 1- (2,4'-dichloro)-phenyl-3-methyl-5pyrazolone, are dissolved in 200 parts of water at 95 and, after the addition of a solution-neutralized with the aid of sodium hydroxide-of 3 parts of crystalline sodium bichromate and 20 parts of water, the resultant mixture is boiled for 9 hours under reflux. The resultant chromium-containing azo dyestulf is precipitated from the metallization solution by the addition of sodium chloride, after which it is filtered off and dried at 70". It corresponds to the formula --OC-N@cl H o H c N'==N c c/ I a a O\ /NO:S

2C- aC and is a yellow powder which dyes wool, silk and synthetic polyamide fibers from a weakly acid bath in yellow shades which are fast to light, washing and fulling.

Example 4 By replacing the 23 parts of l-carboxy-Z-aminobenzene-S-sulfonic acid methylamide in Example 1' by the equivalent quantity of 1-carboxy-2-aminobenzene-S-sulfonic acid-(3'-methoxy) -propylamide, while otherwise proceeding as described in the said. example, there is obtained a monoazo dyestnfi, the chromium complex compound of which corresponds to the formula O-Imms 6 and, in the ground state, is a reddish yellow powder which dyes wool by the afterchroming process or by the single bath chroming process in yellow shades which are fast to light, washing and fulling.

Example 6 The cold solution of 23 parts of diazotized l-carboxy- Z-aminobenzene-S-sulfonic acid methylamide is added to a cold solution of 23.5 parts of 1-naphthyl(l') -3- methyl-S-pyrazolone (melting point=170172) in 400 parts of water and 40 parts of 30% aqueous sodium hydroxide solution. The mass is stirred at 0-5 until the coupling is completed. After the addition of sodium bicarbonate to the coupling mass, the precipitated monoazo dyestulf is filtered off and then dried at 95 under reduced pressure. A yellow powder is obtained which corresponds to the formula and dissolves with greenish yellow coloration in water and in dilute aqueous sodium hydroxide solution and with yellow coloration in concentrated sulfuric acid, and dyes wool by the single bath chroming process in pure yellow shades which are fast to light, fulling and carbonization.

Example 7 mium-containing azo dyestutf is filtered off and dried at It corresponds to the formula 000- 91 OC-N II a N'=N--CC t HaO-HNO:

and is a dark yellow powder which dissolves with yellow coloration in dilute aqueous sodium hydroxide solution and with greenish yellow coloration in concentrated sulfuric acid, and dyes wool, silk and synthetic polyamide fibers in pure yellow shades which are fast to light, washing and fulling.

The following table sets forth additional monoazo dyestuffs according to the present invention, which are suitable for use according to the single bath chroming process, and also chromium-containing azo dyestuffs. The dyestuffs can be prepared according to procedures set forth in the foregoing examples. They are characterized in the table by the diazo components (column A) and by the azo components (column B). Column C sets forth their suitability, and columns (D) and (E) indicate the shades of the corresponding dyeings on wool -and, in some cases, on synthetic polyamide fiber.

. satin Shade on- Exgrmple Diazo Component Azo Component Suitable as- Wool Nylon (A) (B) (C) (D) (E) 8 N l-o9-rb0xy-2-amino-benzene-5- 1-phenyl-3-methyl-5- pyrazo- Metaehrome dyestufl and yellowyellow sullonic acid-(2'-rnethoxy)- lone. chromium complex for ethylamidc, wool and nylon.

9 1-earboxy-Z-amino-benzcne-4- do Chromium complex (or wool. ...d

sulionic acid methyl-amide.

l0 l-carboxy-Z-amino-benzeneido do --.d0...-.--

sultonic acid-(3-rnethoxy)- propylamide. I

11 1-carboxy-2-amino-benzene-S- 1-(3-cyun0)phenyl-3-methyl- Metachrome dyestufland 1 sulionic acid methylarnide. -pyrazolone. chromium complex ior wool and nylon 12 do 1-(4'-cyano)-phcnyl-3-mcthyl- Undo.

B-pyrazolone.

13 do 1-(3-chloro-4'-cyano)phenyb do 3-methyl-5-pyrazolone.

l4 1-carboxy-2-ammo-bcnzene-5- 1-phenyl-3-methyl- 5-pyraz- Metachrome dyestufl un sulfonic acid naphthyl(1)- olone. amide.

15 lcarboxy-Z-aminobenzene-5- .do -d0 c- --"-d sull'onic acid benzylamide.

l6 1carboxy-2-amino-benzenedo ..do .do,

fi-sulfonie acid oyclohcxylamide.

17 1-carboxy-2-amino-benzenedo do brownish 5-sulionic acid-(5, 6, 7, 8- yellow. tctr thydro) naphthyl (1) 18 1-csrboxy-z-emlno-bonzone-s- 1-(3-bromo)phenyl-3-rnethyl- Metochrome dyestufl and yellow. yellow.

sulfonic acid-(3-rnethoxy) fi-pyrazolone. chromium complex to: propylaniide. wool and nylon.

19 do 1-(2, 3-dicl1loro) phenyl-Ii- Chromium complex iorwopl do Do.

methyl-fi-pyrazolone. and nylon.

20 i-carboxy-2-a1nino-benzene-5- l-phcnyl-Ii-methyl-5-pyrazo- Metachromc dyestufl do.

sulfonic acid (4 chloro) lone. phenylamide.

1-carboxy-2-an1ino-benzene-5- l-(3'-ehloro)-phenyl3-methyldo do...

sulfonic acid phenylamidc. S-pyrozolone. do 1-(4'-ethyl)phenyl-B-methyl- ...do do s-pyrazolone. l-carboxy2-amin0-benzeno-5- 1-( 6, 7, 8'-tetrahydro)- Chromium complexior wool ..do-. yellow.

sullonic acid metbylamide. naphthy1(2) 3 methyl 5 and ny on.

pyrazolone.

24 do 1-(1, 2, 3', 4 tetrahydro) do -..do Do naphthyl(2) 3- methyl- 5- pyrazolone.

1-corboxy-2-amino-benzene-5- 1 decahydronaphthylfl) 3 do ..do Do.

snlionic acid ethyl-amide. methyl-fi-pyrazolone.

l-oorboxy-2-amino-benzene-5- l -naphthyl(2) 3 methyl 5 do do Do.

sulionie acid methylamlde. pyrazolone.

27 do... 1-(4-methoxy)-phenyl-3- do do Do.

methyl-5-pyrazolone.

l-(2',5-dlethoxy)-pheny1-3- do .-do Do.

mothyl-5-pymzolone.

1-(3,5-dimethyl)phenyl-3- ...--do do D0.

methy1-5-pyrazolone.

30 1-carboxyQ-amino-benzene-S- 1-phenyl-3-methyl-5pyrazo- ...do.. do Do.

sulionic acid pyrrolldide. lone.

31 l-carboxy-2-amlno-benzene-5- do Metaehrome dyestufi .do

sulionic acid (2 phenyl) ethylamide.

Example 32 A dyebath is prepared from 4000 parts of water, 1 part Example 33 100 parts of wool are entered, at 40", into a dyebath consisting of 1 part of the chromium-containing azo dyestuif obtainable according to Example 1, 4000 parts of water and 5 parts of ammonium sulfate. The bath is heated to boiling in the course of 30 minutes and is then maintained at boiling temperature for minutes. After cooling for a short time, the dyed wool is withdrawn from the bath, washed with water and dried.

Synthetic polyamide fibers are dyed in similar manner, as is also silk, although in the latter case the temperature is maintained somewhat lower, e. g. at

Having thus disclosed the invention, what is claimed is:

1. An azo dyestufi of the pyrazolone series which cor- The bath is responds to the formula G00: z-CC-N-Ri 1\1 N=N-CC CH: R1

wherein R stands for a member selected from the group consisting of lower alkyl, lower alkoxyalkyl, cycloalkyl, aralkyl and aryl groups of the benzene and naphthalene series, free from sulfonic acid and carboxylic acid groups, R stands for a member selected from the group consisting of hydrogen, lower alkyl and, together with N and --R a heterocyclic radical, R stands for a member selected from the group consisting of naphthyl, tetrahydronaphthyl, decahydronaphthyl and groups, x stands for a member selected from the group consisting of "hydrogen and a valence bond to a chromium atom, y and z stand for members selected from the group 9 10 consisting of hydrogen, chlorine, bromine, cyano, lower 5. The azo dyestufl of the pyrazolone series, which coralkyl and lower alkoxy, and wherein the responds to the formula /R1 SO:N 01

OCN-

group 1s m para-position to one of the substituents -COOx 0 and N=N-, and the substituents y and 2 stand in one (1H9 of positions 2, 3', 4 and 5' of the benzene nucleus A. Rio-115x013- 2. The azo dyestuif of the pyrazolone series, which corres ends to the formula p 6. The azo dyestufi of the pyrazolone series, which cor- COOH responds to the formula 3. The azo dyestufi of the pyrazolone series, which cor- H;(H1,mmoflwfmqoz responds to the formula GO OH HO-C-N \N References Cited in the file of this patent o UNITED STATES PATENTS 1 1,623,005 Gubler et a1 Mar. 29, 1927 3 1 814 21s Holzach et a1 Ju1 14 1931 H (}HNO 5 5 5 a 2 2,437,645 Long et a1 Mar. 9, 1948 2,476,259 Mayer et a1 July 12, 1949 g g r fi the pyrazolone serles, whlch 2,565,898 Widmer et a1 Aug 28, 1951 5 6 a 2,606,185 Widmer et a1 Aug. 5, 1952 2,714,102 Schetty July 26, 1955 I II N ---=NC? CH;

Ego-BNO:

U. S. DEPARTMENT OF COMMERCE PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 2, 821,524 Piero Maderni et al.

Column 3, line 30, after 'oI' 2,5-" insert or 3',4- or 3,5

positions by halogen or cyano, lower column 4, line 20, after "8.3" insert parts Signed and sealed this 17th day of June 1958.

(SEAL) Atfiest:

R AXLINE ROBERT c. WATSON Attesting Officer Conmissioner of Patents 

1. AN AZO DYESTUFF OF THE PYRAZOLONE SERIES WHICH CORRESPONDS TO THE FORMULA 